Split expansion-bit for drilling oil-wells.



No. 690,359. Patent'ed Dec. 3|, I90L.

A. B. BURT.

SPLIT EXPANSION BIT FOR DRILLING OIL WELLS.

(Application filed July 26, 1901.}

(No Model.)

1 m m C a F a W a "W52 AW m L l UNITED STATES ANDREIV B. BURT, OF REDLANDS CALIFORNIA.

SPLIT EXPANSION-BIT FOR DRILLING OIL-WELLS.

SPECIFICATION forming part 01? Letters Patent No. 690,359, dated. December 31, 1901.

I Application filed July 26, 1901. Serial No- 69,835. (No model.)

To (all whom, it nay concern:

Be it known that I, ANDREW B. BURT, a

citizen; of the UnitedStates, residing at-Redlands, county of San Bernardino, State of California, have invented certain new and useful Improvements in Split Expansion -Bits for Drilling Oil-Wells, of which the following is a specification- Myinvention relates to split expansion-bits for drilling oil-wells and other purposes.

The object of the invention is the provision of a bit of improved and novel construction which can be used in place of the ordinary solid bit in oil-welldrilling and as an underreamer. More particularly, I aim to provide a novel bit which, while adapted for use in place of a solid bit, will be arranged to automatically extend or expand after it leaves the casing for purposes of underreaming and will be capable of use in deposits of all kinds.

Having the foregoing objects in view/the invention consists of a device of the class described comprising certain improved features and novel combinations of parts, set forth in detail hereinafter, and recited in the appended claims.

In the accompanying drawings, Figure 1 is a side View with parts broken away to illustrate the interior construction; Figs. 2 and 3, end views, and Fig. 4 a side view taken at right angles to Fig. 1.

The numeral 1 designates a flattened head provided with a transverse slot 2 therein, while 3 and 4 are the bit members, which have reduced portions 5 pivoted in the slot 2 on bolts 6 and 7, so that the said bit members are adapted to spread laterally. As shown in Fig. 3, the bit members have their sides grooved longitudinally at 8 and 9 to provide the cutting edges, while their ends are recessed at 10, as usual. Extending through the bit members from their outer to their inner faces are apertures 11, intercepted intermedi ate their ends by the webs 12, having the central perforations or apertures 13.

The numeral 14 designates a pin having threaded portions 15,0n which are nuts 16,0utside the webs 12, while a coil-spring 17 surrounds the pin and is interposed between the said webs, the tendency of said spring being to press on said webs and force the bit members apart, the latter turning on their pivots. In using the bit in the usual manner in drilling it would be adapted for use as a solid bit by screwing-up the nuts to prevent the bit members from springing apart by the action of the spiral spring. l-Vhen it is desired to adapt the device for underreaming, the nuts 16 are unscrewed a sufficient distance to give the proper expansion of the members, whereupon the coil-spring will press on the webs and force said members apart, it being clear that there is nothing to hinder the said members from approaching each other according to requirements.

, I am aware that changes of construction might be resorted to, but without materially differentiating the invention from the disclosures herein shown; and I do not, therefore, limit myself to the precise construction herein shown and described, but consider that I am entitled to all such changes as come within the spirit and scope of the invention.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a split expansion-bit, the combination with a head, of bit members pivoted thereto which have apertures extending therethrough transversely and Webs intercepting said apertures and themselves having smaller apertures, a pin extending through the apertures in the webs and into the main apertures, a spiral spring surrounding said pin and interposed between the webs, and heads on the pin which are adapted to limit the outward spread of the bits.

2. In a split expansion-bit, the combination with a head, of bit members pivoted thereto which have apertures extending therethrough and webs intercepting said apertures and themselves having smaller apertures, a pin extending through the apertures and having stop members adj ustable longitudinally there on in the apertures outside of the webs, and o selves having apertures of smaller-size, a pin In testimony whereof I hereunto affix my extending through the aperturesof the webs signature in presence of two witnesses.

and in to the main apertures which has serewthreaded portions on its ends, nuts threaded onto said ends outside of the webs, and a Witnesses: spiral spring surrounding the pin and inter- JAMES BURT, posed between the bits. GEO. A. PEARSONS.

ANDREW B. BURT. 

